PDA

View Full Version : 375 H&H and 375449jn load development



AlaskanGuy
01-25-2014, 10:02 PM
Well, as most of you guys know, i have been working on bear loads with cast for my Browning A-Bolt 375 H&H and the Lyman 375449JN 94617

.... The gun is a great shooter with jacketed stuff like A-frames and such, and have taken many bears, and moose with it, but never with cast.. So this spring begins the quest to get a mature bear with cast...

The gun needed to be able to group very well at 200 yards.. I really want 3 inch groups.... I know the gun is capable, but couldn't seem to be able to get that even at 100 yards with the 375449 jn....

I started thinking about 4064 after reading some of Beagle's work, and after a couple PM's with him about my intentions, I started working with 4064 and best I could get was around 5 inch groups.. I laddered up through about 52 gr of 4064, changed the seating of the Boolits... Longer shorter, didn't seem to matter... Some of the groups started out ok, but out of 5 shots, there would be a couple flyers... Just not getting it done.... But, but..... It worked for Mr. Beagle.... It just wouldn't work for me...

I PM'ed a certain rocket scientist that hangs around on this board, explained the situation, and he suggested 4350, starting at 43gr and working through about 55 grains.... And what do you know, the old A-Bolt likes it.... Turns out the magic number where things really start shooting good is about 49 gr... I had a bunch of targets marked out for 100 yards, but things were going so good I pulled a target off and moved the 100 yard paper to 200 yards just to see what would happen at 200....

See for yourself.... First is 100 yds... 94610

200 yards.... 94611

I know I can tighten things up on the 100 yard target to less then 1 inch... And that will also tighten up my 200 yd group... Things are really showing promise though with the 4350.... I am going to continue pushing up the powder in 1/2 grain increments till it starts going bad..... Today was the first day of the 4350 trials, and I am stoked.... Just wish I had a chrony so I could check speed... Not much reference for H4350....

Thanks Beagle, and Mr. Rocket Scientist.... For all the help..

AlaskanGuy

AlaskanGuy
01-25-2014, 10:21 PM
These are the alloy development pics

94619

94620

starmac
01-25-2014, 10:29 PM
I knew there was a reason to pick up my limit of 4350 when it was available. lol
It is looking pretty good, are you going to try any powder coated?

btroj
01-26-2014, 12:37 AM
Is that with or without a filler? I have some IMR 4350 looking for a use.

AlaskanGuy
01-26-2014, 03:21 AM
I used a small tuff of Dacron filler to hold the powder in place...... I am totally stoked now that i am getting closer to my final bear load....

AG. :o

btroj
01-26-2014, 08:52 AM
I need to try that load. I have a few pounds of 4350 looking for a good use.

Any idea on velocity? I would expect 2100 or there abouts.

Looks like a winner, unless you are a bear.....

AlaskanGuy
01-26-2014, 12:59 PM
I would expect around 2050 or so, but have no access to a chrono, and there is no published data for that load... At least none that I could find.....

swheeler
01-26-2014, 01:13 PM
Sounds like you talked to the "right" rocket scientist! That guy has probably tried the same powder and dacron in his M70, could very likely give you the pressure it is operating at. Cast boolit browny in your future?

AlaskanGuy
01-26-2014, 01:58 PM
I am hoping so... I have promised my 17 year old son to take him on a brown bear hunt this spring... Boat based, spot and stalk... I dont normally hunt brownies, but i have always wanted to get one with a bow, and one with cast... So, looks like a father son thing... Just hope we can find a mature one in Prince William Sound... Lots of bears... And the Rocket Scientist is Larry Gibson... Not much he doesnt know about cast, and reloading in general... When he gives advice, i try to write it down.... :drinks:

AG

swheeler
01-26-2014, 02:35 PM
Sounds like fun and good memories for you and your son. I guessed it was Larry, and yes when he recommends something I listen too, quite a knowledge base there, first hand experience counts.

TXGunNut
01-27-2014, 11:47 PM
Got any 4895? Looking good but I've been fooled by 3-shot groups.

rockrat
02-01-2014, 06:08 PM
Or 4759? My Ruger #1 is showing promise with 4759 and the NOE 378-275, Velocities are near 2100fps and next range trip, will probably crack that.